Perception

The process of organizing and interpreting information, enabling us to

recognize meaningful objects and events.

Perception• The active process of

selecting, organizing, and interpreting the information brought to the brain by the senses

• Perception is the way we interpret sensations and therefore make sense of everything around us

• Example:

Top Down Processing• Processing information from

the senses with higher level mental processes using our experiences and expectations

• Using your background knowledge to fill in the gaps

• Examples:

Gestalt Psychology• Gestalt - focused on how we GROUP objects

together as an organized whole.

• Example:

Figure Ground RelationshipFigure –ground - Our first perceptual decision is what in the image is the figure and what is the background.Example:

Grouping•Grouping – tendency to organize stimuli into coherent groups and not isolated elements.•Examples

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Depth Cues• Depth Perception – allows us

to judge distance because we see thing in three dimension even though images strike retina in two dimensions

• Visual Cliff Experiment - Eleanor Gibson – If you are old enough to crawl,

you are old enough to see depth perception.

• See depth by using two cues• Examples

Binocular Cues• Binocular cues –

depth cues that depend on the use of two eyes.

• Examples:

Monocular Cues• Monocular cues –

depth cues available to either eye alone

• Examples:

Interposition

Relative Size

Relative Height

Horizontal vertical illusion

Linear Perspective

Relative Motion

Light and Shadow

Texture Gradient

Perceived Motion• Stroboscopic effect – continuous

movement in a rapid series of slightly varying images– Example:

• Phi phenomenon – an allusion created when two or more adjacent lights blink on and off in quick succession

• Example:

Constancy• Perpetual constancy –

perceiving objects as unchanging even as illumination and retinal images change• Objects change in our

eyes constantly as we or they move….but we are able to maintain content perception

• Examples

Perceptual Constancy• Shape constancy –

Perceptual Constancy

• Shape Constancy illusion– some times we perceive the shape of something to change with the angle of our view

Perceptual Constancy• Size constancy –

Perceptual Constancy• Size constancy illusion–

sometimes perceive objects as having a changing size because of the interplay between perceived size and distance

• Moon illusion

• Ponzo illusion

Ames Room

Lightness Constancy• Lightness constancy

aka Brightness constancy – perceiving an object as having constant lightness even while its illumination varies.

• Depends on…– Relative luminance –

the amount of light an object reflects relative to its surroundings

Color Constancy• Color constancy – perceiving

familiar objects as having constant color, even if changing illumination alters the wavelengths reflected by the object

• Depends on what we’re comparing it to…– Surrounding context – color

comes not only from the wavelength information received by cones, but also from the surrounding context

– Surrounding objects – light is reflected not only from the object, but other objects surrounding it.

Example:

Perceptual Interpretation

Sensory Deprivation and Restored Vision

• Experiments on sensory deprivation–Brains cortical cells don’t develop normal connections

–Critical period

Perceptual Adaptation

Perceptual adaptation – the ability to adjust to artificially displaced or inverted visual field

Example:

Perceptual SetPerceptual set (aka mental predisposition) –

mental predisposition to perceive one thing and not another– Schemas – concepts that organize and

interpret unfamiliar info/ambiguous situations Examples:

Context Effects• Context effects – perceptual

set can be influenced by the context (expectations and emotions, and motivations)

• Examples:

Perception is a Biopsychosocial Phenomenon

Is There Extrasensory Perception?

Parapsychology

Claims of ESP• Parapsychology – study of paranormal phenomena

including ESP and psychokinesis• Extrasensory Perception – claim that perception can

occur apart from sensory input Examples:

• Psychokinesis (PK) – mind over matter (levitation)